1 //===-- asan_linux.cc -----------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is a part of AddressSanitizer, an address sanity checker.
12 // Linux-specific details.
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_common/sanitizer_platform.h"
16 #if SANITIZER_FREEBSD || SANITIZER_LINUX
18 #include "asan_interceptors.h"
19 #include "asan_internal.h"
20 #include "asan_thread.h"
21 #include "sanitizer_common/sanitizer_flags.h"
22 #include "sanitizer_common/sanitizer_freebsd.h"
23 #include "sanitizer_common/sanitizer_libc.h"
24 #include "sanitizer_common/sanitizer_procmaps.h"
27 #include <sys/resource.h>
29 #include <sys/syscall.h>
30 #include <sys/types.h>
39 #include <sys/link_elf.h>
42 #if SANITIZER_ANDROID || SANITIZER_FREEBSD
44 extern "C" void* _DYNAMIC;
46 #include <sys/ucontext.h>
50 // x86-64 FreeBSD 9.2 and older define 'ucontext_t' incorrectly in
52 #if SANITIZER_FREEBSD && (SANITIZER_WORDSIZE == 32) && \
53 __FreeBSD_version <= 902001 // v9.2
54 #define ucontext_t xucontext_t
58 ASAN_RT_VERSION_UNDEFINED = 0,
59 ASAN_RT_VERSION_DYNAMIC,
60 ASAN_RT_VERSION_STATIC,
63 // FIXME: perhaps also store abi version here?
65 SANITIZER_INTERFACE_ATTRIBUTE
66 asan_rt_version_t __asan_rt_version;
71 void DisableReexec() {
72 // No need to re-exec on Linux.
76 // No need to re-exec on Linux.
79 void *AsanDoesNotSupportStaticLinkage() {
80 // This will fail to link with -static.
81 return &_DYNAMIC; // defined in link.h
85 // FIXME: should we do anything for Android?
86 void AsanCheckDynamicRTPrereqs() {}
87 void AsanCheckIncompatibleRT() {}
89 static int FindFirstDSOCallback(struct dl_phdr_info *info, size_t size,
91 // Continue until the first dynamic library is found
92 if (!info->dlpi_name || info->dlpi_name[0] == 0)
96 if (internal_strncmp(info->dlpi_name, "linux-", sizeof("linux-") - 1) == 0)
99 *(const char **)data = info->dlpi_name;
103 static bool IsDynamicRTName(const char *libname) {
104 return internal_strstr(libname, "libclang_rt.asan") ||
105 internal_strstr(libname, "libasan.so");
108 static void ReportIncompatibleRT() {
109 Report("Your application is linked against incompatible ASan runtimes.\n");
113 void AsanCheckDynamicRTPrereqs() {
114 // Ensure that dynamic RT is the first DSO in the list
115 const char *first_dso_name = 0;
116 dl_iterate_phdr(FindFirstDSOCallback, &first_dso_name);
117 if (first_dso_name && !IsDynamicRTName(first_dso_name)) {
118 Report("ASan runtime does not come first in initial library list; "
119 "you should either link runtime to your application or "
120 "manually preload it with LD_PRELOAD.\n");
125 void AsanCheckIncompatibleRT() {
127 if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
128 __asan_rt_version = ASAN_RT_VERSION_DYNAMIC;
129 } else if (__asan_rt_version != ASAN_RT_VERSION_DYNAMIC) {
130 ReportIncompatibleRT();
133 if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
134 // Ensure that dynamic runtime is not present. We should detect it
135 // as early as possible, otherwise ASan interceptors could bind to
136 // the functions in dynamic ASan runtime instead of the functions in
137 // system libraries, causing crashes later in ASan initialization.
138 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
140 while (proc_maps.Next(0, 0, 0, filename, sizeof(filename), 0)) {
141 if (IsDynamicRTName(filename)) {
142 Report("Your application is linked against "
143 "incompatible ASan runtimes.\n");
147 __asan_rt_version = ASAN_RT_VERSION_STATIC;
148 } else if (__asan_rt_version != ASAN_RT_VERSION_STATIC) {
149 ReportIncompatibleRT();
153 #endif // SANITIZER_ANDROID
155 void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
157 ucontext_t *ucontext = (ucontext_t*)context;
158 *pc = ucontext->uc_mcontext.arm_pc;
159 *bp = ucontext->uc_mcontext.arm_fp;
160 *sp = ucontext->uc_mcontext.arm_sp;
161 #elif defined(__aarch64__)
162 ucontext_t *ucontext = (ucontext_t*)context;
163 *pc = ucontext->uc_mcontext.pc;
164 *bp = ucontext->uc_mcontext.regs[29];
165 *sp = ucontext->uc_mcontext.sp;
166 #elif defined(__hppa__)
167 ucontext_t *ucontext = (ucontext_t*)context;
168 *pc = ucontext->uc_mcontext.sc_iaoq[0];
169 /* GCC uses %r3 whenever a frame pointer is needed. */
170 *bp = ucontext->uc_mcontext.sc_gr[3];
171 *sp = ucontext->uc_mcontext.sc_gr[30];
172 #elif defined(__x86_64__)
173 # if SANITIZER_FREEBSD
174 ucontext_t *ucontext = (ucontext_t*)context;
175 *pc = ucontext->uc_mcontext.mc_rip;
176 *bp = ucontext->uc_mcontext.mc_rbp;
177 *sp = ucontext->uc_mcontext.mc_rsp;
179 ucontext_t *ucontext = (ucontext_t*)context;
180 *pc = ucontext->uc_mcontext.gregs[REG_RIP];
181 *bp = ucontext->uc_mcontext.gregs[REG_RBP];
182 *sp = ucontext->uc_mcontext.gregs[REG_RSP];
184 #elif defined(__i386__)
185 # if SANITIZER_FREEBSD
186 ucontext_t *ucontext = (ucontext_t*)context;
187 *pc = ucontext->uc_mcontext.mc_eip;
188 *bp = ucontext->uc_mcontext.mc_ebp;
189 *sp = ucontext->uc_mcontext.mc_esp;
191 ucontext_t *ucontext = (ucontext_t*)context;
192 *pc = ucontext->uc_mcontext.gregs[REG_EIP];
193 *bp = ucontext->uc_mcontext.gregs[REG_EBP];
194 *sp = ucontext->uc_mcontext.gregs[REG_ESP];
196 #elif defined(__powerpc__) || defined(__powerpc64__)
197 ucontext_t *ucontext = (ucontext_t*)context;
198 *pc = ucontext->uc_mcontext.regs->nip;
199 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
200 // The powerpc{,64}-linux ABIs do not specify r31 as the frame
201 // pointer, but GCC always uses r31 when we need a frame pointer.
202 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
203 #elif defined(__sparc__)
204 ucontext_t *ucontext = (ucontext_t*)context;
206 # if defined (__arch64__)
207 *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
208 *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
209 stk_ptr = (uptr *) (*sp + 2047);
212 *pc = ucontext->uc_mcontext.gregs[REG_PC];
213 *sp = ucontext->uc_mcontext.gregs[REG_O6];
214 stk_ptr = (uptr *) *sp;
217 #elif defined(__mips__)
218 ucontext_t *ucontext = (ucontext_t*)context;
219 *pc = ucontext->uc_mcontext.gregs[31];
220 *bp = ucontext->uc_mcontext.gregs[30];
221 *sp = ucontext->uc_mcontext.gregs[29];
223 # error "Unsupported arch"
227 void AsanPlatformThreadInit() {
228 // Nothing here for now.
231 #if !SANITIZER_ANDROID
232 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
233 ucontext_t *ucp = (ucontext_t*)context;
234 *stack = (uptr)ucp->uc_stack.ss_sp;
235 *ssize = ucp->uc_stack.ss_size;
238 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
243 void *AsanDlSymNext(const char *sym) {
244 return dlsym(RTLD_NEXT, sym);
247 } // namespace __asan
249 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX